The ASPTC is a type E thermocouple housed in a white, elongated radiation shield. The radiation shield reduces solar loading on the thermocouple by drawing air across the measurement junction with a fan. The radiation shield also protects the thermocouple, increasing its durability.
Typically, one ASPTC is mounted to each sensor arm in a Bowen ratio system. One ASPTC can either replace, or be measured in addition to, TCBR thermocouples. In a standard configuration, lead lengths of 15 feet are recommended for both signal and power cables.
- Uses fine wire thermocouple for highly accurate air temperature measurements
- Includes aspirated radiation shield
- Solar loading on thermocouple reduced by drawing air across the measurement junction with a high-powered fan
- Intake velocity is 5.5 m/sec
- Fan requires 12 Vdc power supply
- Fan average active current drain is 142 mA
- Weight: 1.9 lbs (0.86 kg); 1.6 lb (0.7 kg) without cable
- Length: 21" (53.3 cm)
- Height: 5.8" (14.7 cm)
- Large diameter: 2.3" (5.8 cm)
- Small diameter: 1.8" (4.6 cm)
- Power cable diameter: 0.2" (0.5 cm)
- Signal cable diameter: 0.1" (0.3 cm)